I realize shooting an entire film that way isn't feasible, I just posted those photos for reference. There had to be a way they could get the finished shots to more closely resemble what being underwater actually looks like.
Even JL managed it better:
Whatever you're seeing, you're the only one seeing it lol. The only difference is murkier water and Jason Momoa looking like he was holding his breath. Neither of those makes it look more realistic.
